AWS C5 Vs. M5 Instances: A Side-By-Side Comparison

Amazon EC2 M5 and C5 instances offer high performance for both compute- and memory-intensive applications. A C5 instance delivers more compute capacity than memory, whereas a M5 instance balances compute, memory, and network bandwidth.

This guide compares C5 vs. M5 instances, including types, sizes, and ideal uses of each. We’ll also share a tool you can use to choose the right instance type for your applications based on factors such as AWS service, resource type, and instance pricing.

What Are Amazon EC2 C5 Instances?

Amazon C5 instances are part of the Compute-Optimized category of AWS instances. The higher CPU-to-memory ratio in C5 instances enables them to deliver high performance for compute-intensive applications.

Compared to some General Purpose instances of the size, C5 instances have less memory but charge a lower per-hour on-demand pricing.

Currently, there are five types of C5 instances: C5, C5n, C5a, C5d, and C5ad.

Amazon EC2 C5 instances

C5 instances offer better performance than C4 instances. They use Intel Xeon Platinum 8000 series processors, clocked up to 3.6GHz (Cascade Lake or Skylake-SP). A 2nd generation Intel Xeon Scalable (Cascade Lake) processor powers the largest C5 instances.

In addition, these instances come with a network bandwidth of between 10 Gbps and 25 Gbps, and up to 19 Gbps of dedicated Amazon EBS capacity. They also feature AWS Nitro, which includes the Nitro hypervisor, Nitro security chip, and Nitro card.

Amazon EC2 C5n instances

C5n instances have similar vCPUs, but more memory (up to 192 GIBs) than compatible C5 instances. These processors are capable of processing large amounts of data quickly, such as High Performance Computing (HPC) workloads.

For example, C5n instances have a network capacity of up to 100 Gbps, run on AWS Nitro System, and can use up to 32 queues for packet processing compared to just 8 queues with C5 and C5d instances.

Amazon EC2 C5a instances

C5a instances are powered by AMD processors (2nd generation, 3.3 GHz EPYC 7000 series) designed to optimize price-performance for compute-intensive workloads. Expect up to 20 Gbps of network bandwidth paired with a dedicated speed of 9.5 Gbps to Amazon EBS.

Amazon EC2 C5d instances

C5d instances offer similar vCPU and memory capacities as C5 instances, with local NVMe-based SSDs attached to the physical host server. Also, expect block-level storage that’s coupled to the lifetime of the C5d instance.

Amazon C5ad instances

As with C5a instances, C5ad instances run on AMD processors, offering a combination of X86 price-performance, 20 Gbps maximum network bandwidth, 9.5 Gbps of dedicated bandwidth via Amazon EBS, and physically connected, local NVMe-based SSDs for block-level storage that’s coupled to the instance’s lifetime.

What Are Amazon EC2 M5 Instances?

Amazon M5 instances belong to the General Purpose category of AWS instances. They deliver balanced vCPU, memory, and network capacity. M5 instances are ideal for powering a variety of workloads due to their consistency.

We’ve covered M5 instances in a lot more detail in our Amazon M5 instances guide here.

M5 instances come in seven varieties: M5, M5n, M5a, M5d, M5dn, M5ad, and M5zn.

Amazon EC2 M5 instances

A C5 instance uses a 3.3 GHz Intel Xeon Platinum 8000 series processor, whereas an M5 instance uses a 3.1 GHz version. However, M5 instances support the latest Intel Advanced Vector Extensions 512 (AVX-512). This instruction set offers up to 2X the FLOPS per-core over M4 instances.

Amazon EC2 M5n instances

AWS optimized M5n instances to deliver superior networking (up to 100 Gbps and 19 Gbps dedicated capacity to Amazon EBS) compared to other compatible M5 instances. This configuration is ideal for medium- to high-performance requirements, such as convolution in machine learning.

Amazon EC2 M5a instances

These AMD-powered instances deliver outstanding price-performance for workloads that require consistent and balanced CPU, memory, and network bandwidth. M5a instances are powered by 2.5 GHz processors.

Amazon EC2 M5d instances

M5d instances deliver fast storage — local NVMes–based SSDs that are affixed to the host servers. They also deliver block-level storage that’s coupled throughout the instance’s lifetime.

Amazon EC2 M5dn instances

M5dn and M5n instances have similar processors and superior network bandwidth to process massive volumes of data rapidly. Expect up to 19 Gbps speeds through Amazon EBS and up to 100 Gbps network capacity.

Amazon EC2 M5ad instances

For general-purpose workloads where you want to balance price and performance, choose M5ad instances. These AMD-based instances clock at 2.5 Ghz but offer impressive block-level storage speeds.

Amazon EC2 M5zn instances

This is the newest addition to the M5 family of AWS instances, delivering the fastest processing speeds (4.5 Ghz all core Turbo). M5zn instances are ideal for use cases that require extremely high throughput, single-thread performance, such as simulation modeling in aerospace and low latency networking in telecommunications.

C5 Vs. M5 Instances: A Side-by-Side Comparison Table

To help you decide which instance type matches your computing needs on AWS, we have compared the base C5 and M5 instances side-by-side below.

	Amazon EC2 M5 instances	Amazon EC2 C5 instances
Speciality	General purpose applications with balanced CPU, memory, and networking capacity	Compute-intensive use cases, needing higher CPU performance vs memory
Supported processors	1st or 2nd generation Intel Xeon Platinum 8000 series (Cascade Lake or Skylake-SP), clocked up to 3.1 GHz (all-core turbo), with support for Intel Advanced Vector Extensions 512 (AVX-512) instruction set for 2X better FLOPS per-core performance over M4 instances AWS Nitro System	1st or 2nd generation Intel Xeon Platinum 8000 series (Skylake-SP), clocked up to 3.4 GHz (all-core turbo) or 3.5 GHz (single-core turbo) 12xlarg, 24xlarge, and metal instance sizes use 2nd generation, Intel Xeon Scalable (Cascade Lake) processors, clocked up to 3.6 GHz (all-core turbo) AWS Nitro System
Number of cores	Up to 48 CPU cores per instance for the M5.24xlarge size	Up to 48 CPU cores per instance for the C5.24xlarge size
Maximum Memory	384 GiB	192 GiB
Instance sizes available	m5.large m5.xlarge m5.2xlarge m5.4xlarge m5.8xlarge m5.12xlarge m5.16xlarge m5.24xlarge	c5.large c5.xlarge c5.2xlarge c5.4xlarge c5.9xlarge c5.12xlarge c5.18xlarge c5.24xlarge
Network bandwidth	Up to 25 Gbps	Up to 25 Gbps
EBS Bandwidth	19 Gbps	19 Gbps
Best use cases	Small and mid-sized web app servers, databases, websites, app dev environments, and cluster computing workloads	High-performance web app servers, ad serving, HPC, batch processing, scientific modeling, multiplayer gaming, video encoding, and deep machine learning

Choose The Right Instances For Your Applications With CloudZero Advisor

CloudZero Advisor’s recommendations help you avoid overprovisioning (wasting resources and increasing costs) or underprovisioning (degrading performance or causing downtime).

With Cloud Advisor, you can rightsize your AWS instances from the very start based on factors such as pricing, AWS service, resource type, and instance name, type, and size.

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